It's the binary news events -- clinical trial results and Food and Drug Administration approvals -- that make drug developers so fun to invest in, and so hard to stomach ... sometimes all at the same time. Let's take a look at a few companies expecting FDA decisions this month and see whether they're more likely to get a present or a lump of coal in their marketing-application stockings.

I'm dreaming of a ... pain-free Christmas
Drugmakers King Pharmaceuticals (NYSE:KG) and Pain Therapeutics (NASDAQ:PTIE) are hoping to make money off of Perdue Pharma's OxyContin. Remoxy is an abuse-resistant version of Perdue's painkiller designed using Durect's delivery system.

The only question is how "abuse-resistant" the drug really is. The FDA seemed particularly harsh in documents released to the advisory panel. The agency is worried that the companies didn't test beyond one hour to see if drug addicts could extract the active ingredient from Remoxy by leaving it in solvent. The advisory panel was a little less harsh, with the majority of members saying that the drug was abuse-resistant enough.

We're going into uncharted territory, but it seems ridiculous that the agency is deciding what defines abuse-resistant at this late date. I hope the agency will give Remoxy a thumbs up, but it seems far from a sure thing.

Ironically, the true ability of Remoxy to deter drug abuse will be the street value of the drug once it's on the market. With a PDUFA date set for tomorrow, the drugmakers shouldn't have to wait much longer to find out.

All I want for Christmas is my two ... drugs approved
Genzyme (NASDAQ:GENZ) is like a kid with a birthday around Christmas. It could end up with a double dose of presents from the FDA. The PDUFA date for Mozobil is December 16, and a week later, on December 23, it should hear about Synvisc-One.

Mozobil is designed to help transplant patients undergo successful bone marrow transplants when taken with Amgen's (NASDAQ:AMGN) Neupogen. I think it's likely to get a green light from the FDA, but it won't contribute that much to Genzyme's growth. The company expects annual peak sales of more than $400 million, but it'll take awhile, and probably approvals in other countries, to get there.

Genzyme's other potential Christmas present comes in the form of Synvisc-One, the follow up to its three-shot Synvisc that only requires -- you guessed it -- one shot. The osteoarthritis pain drug is the subject of an FDA advisory panel review today. Considering that the FDA didn't sound too enthused about the size of the clinical trial that Genzyme is using to prove that the drug works, the company could get a lump of coal in its stocking. At least it'll have a good idea which way the agency will lean after the vote today.

Grandma got run over by a ... competing drug
The psoriasis drug market is pretty crowded with Abbott Labs' (NYSE:ABT) Humira, Amgen and Wyeth's Enbrel, and Johnson & Johnson's (NYSE:JNJ) Remicade, which is sold outside the U.S. by Schering-Plough (NYSE:SGP), but Johnson & Johnson and Medarex look like they've got a winner with Stelara (ustekinumab).

The drug beat Enbrel in a head-to-head competition in September, and that'll go a long way toward getting it approved and sold once it's on the market. The drug has some safety issues, but I think the agency is likely to gloss over those, especially since they're common to most biologic anti-inflammatory drugs. The FDA extended its decision by three months, so Johnson & Johnson should hear by the end of the month if it'll be able to market the drug.

Have yourself a merry little ... PDUFA date
It bears a reminder that the PDUFA dates are goals that the FDA sets for itself. While the FDA sometimes hands down decisions on the PDUFA date, the decisions can come earlier or later. Of last month's contenders, two got decisions before their PDUFA date, and one was the last business day before the PDUFA date.

But lately, that seems to be more of an exception than a rule. The FDA still has some applications sitting on its desk that are well beyond the 10-month goal.

Foolish investors won't day trade around these decisions. Instead, they'll pick appropriate entry points, expect delays, and wait for the FDA to eventually get around to approving the compounds.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.